I’ve got a couple older frying pans, and a leg less Dutch oven. Recently got a lodge Dutch oven with legs for outside cooking.
I took an angle grinder with flap disc to the new Dutch oven and smoothed out all the rough spots, it was messy and took a while, but it is extremely smooth now and works great.
A tip that took embarrassingly long to sink in for me is to preheat your pan, I know millions of recipes call for this, but for some reason I never did it and I could get scrambled eggs to be stuck hard onto Teflon when starting with a cold pan, glad I’m smarted now. I cook scrambled eggs several times a week in my cast iron, I turn it on and let it preheat and melt a little bacon grease in it while I’m cracking eggs, pour them in and let them cook for a bit before starting to flip and break them up and they don’t stick at all now, just wipe the pan out when I’m done.
When something does get stuck on I like to just use really hot water and a long handled scrub brush to remove it.